package com.zhu.stack;

import java.util.Stack;

/**
 * leetcode上的括号匹配问题
 * @author: zhu
 * @date: 2019/1/12 08:25
 */
public class UseArrayStack {
    public boolean isValid(String s){
        Stack<Character> stack = new Stack<>();
        for (int i=0;i<s.length();i++){
            char c = s.charAt(i);
            if (c == '(' || c == '[' || c == '{'){
                stack.push(c);
            }else {
                if (stack.isEmpty()){
                    return false;
                }
                char topChar = stack.pop();
                if (c == ')' && topChar != '('){
                    return false;
                }
                if (c == ']' && topChar != '['){
                    return false;
                }
                if (c == '}' && topChar != '{'){
                    return false;
                }
            }
        }
        return stack.isEmpty();
    }
}
